Left atrial appendage treatment systems and methods

ABSTRACT

Embodiments of the present invention encompass systems and methods to prevent complications from atrial fibrillation by preventing or reducing the likelihood of blood flow out of the left atrial appendage, to eliminate a possible source of aberrant electrical circuits, or both. Accordingly, techniques are provided for delivering ligature loops or closure means to the left atrial appendage, and to other anatomical structures of a patient which may be desirable in other surgical procedures.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application continuation U.S. patent application Ser. No.14/593,961 filed Jan. 9, 2015, which is a continuation of U.S. patentapplication Ser. No. 14/244,671 filed Apr. 3, 2014, which is adivisional of U.S. patent application Ser. No. 13/524,891 filed Jun. 15,2012, which claims the benefit of U.S. Provisional Patent ApplicationNo. 61/498,399 filed Jun. 17, 2011, the content of which areincorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Embodiments of the present invention relate to systems and methods forclosing anatomical structures of a patient. Particular embodimentsrelated to techniques for closing the left atrial appendage of apatient.

Atrial fibrillation (AF) is a heartbeat rhythm disorder (or “cardiacarrhythmia”) in which the upper chambers of the heart known as the atriaquiver rapidly instead of beating in a steady rhythm. This rapidquivering reduces the heart's ability to properly function as a pump. AFis characterized by circular waves of electrical impulses that travelacross the atria in a continuous cycle. It is the most common clinicalheart arrhythmia, affecting more than two million people in the UnitedStates and some six million people worldwide.

Atrial fibrillation typically increases the risk of acquiring a numberof potentially deadly complications, including thrombo-embolic stroke,dilated cardiomyopathy and congestive heart failure. Quality of life isalso impaired by common AF symptoms such as palpitations, chest pain,dyspnea, fatigue and dizziness. People with AF have, on average, afive-fold increase in morbidity and a two-fold increase in mortalitycompared to people with normal sinus rhythm. One of every six strokes inthe U.S. (some 120,000 per year) occurs in patients with AF, and thecondition is responsible for one-third of all hospitalizations relatedto cardiac rhythm disturbances (over 360,000 per year), resulting inbillions of dollars in annual healthcare expenditures.

AF is the most common arrhythmia seen by physicians, and the prevalenceof AF is growing rapidly as the population ages. As the prevalence of AFincreases, so will the number of people who develop debilitating orlife-threatening complications, such as stroke. According to FraminghamHeart Study data, the stroke rate in AF patients increases from about 3%of those aged 50-59 to more than 7% of those aged 80 and over. AF isresponsible up to 35% of the strokes that occur in people older than age85.

Efforts to prevent stroke in AF patients have so far focused primarilyon the use of anticoagulant and antiplatelet drugs, such as warfarin andaspirin. Long-term warfarin therapy is recommended for all AF patientswith one or more stroke risk factors, including all patients over age75. Studies have shown, however, that warfarin tends to beunder-prescribed for AF. Despite the fact that warfarin reduces strokerisk by 60% or more, only 40% of patients age 65-74 and 20% of patientsover age 80 take the medication, and probably fewer than half are on thecorrect dosage. Patient compliance with warfarin is problematic, and thedrug requires vigilant blood monitoring to reduce the risk of bleedingcomplications.

Electrophysiologists classify AF by the “three Ps”: paroxysmal,persistent, or permanent. Paroxysmal AF—characterized by sporadic,usually self-limiting episodes lasting less than 48 hours—is the mostamenable to treatment, while persistent or permanent AF is much moreresistant to known therapies. Researchers now know that AF is aself-perpetuating disease and that abnormal atrial rhythms tend toinitiate or trigger more abnormal rhythms. Thus, the more episodes apatient experiences and the longer the episodes last, the less chance ofconverting the heart to a persistent normal rhythm, regardless of thetreatment method.

AF is characterized by circular waves of electrical impulses that travelacross the atria in a continuous cycle, causing the upper chambers ofthe heart to quiver rapidly. At least six different locations in theatria have been identified where these waves can circulate, a findingthat paved the way for maze-type ablation therapies. More recently,researchers have identified the pulmonary veins as perhaps the mostcommon area where AF-triggering foci reside. Technologies designed toisolate the pulmonary veins or ablate specific pulmonary foci appear tobe very promising and are the focus of much of the current research incatheter-based ablation techniques.

One possible complication as a result of AF is that clots from the leftatrial appendage may embolize and cause harm to the patient. Forexample, dislodged clots can form emboli that lead to ischemic damage toa person's brain, kidneys, or other organs. Although left atrialappendage closure devices and techniques are currently available andprovide real benefits to patients in need thereof, significant advancesmay still be made to provide improved systems and methods for treatingthe left atrial appendage. Embodiments of the present invention providesolutions and answers to at least some of these outstanding needs.

BRIEF SUMMARY OF THE INVENTION

Embodiments of the present invention encompass systems and methods fordelivering closure means to an anatomical structure of a patient, suchas a left atrial appendage. Exemplary systems may include a guidingmechanism, closure delivery means, or suture carrier that delivers orapplies a closure means or occlusive device to the patient anatomy. Inuse, for example, a surgeon or operator may obtain or hold a ligatureassembly, which includes a carrier tube and knotted suture loop, andseparate a frangible portion of the carrier tube away from the main bodyof the tube shaft. This may be done by snapping the carrier tube along abreak line which is scored on the tube. Often, a proximal tail of theknotted ligature thread is glued or crimped to, or otherwise attachedwith, the proximal frangible portion of the carrier tube. The user canplace the suture thread loop about a cinchable loop of a deliverymechanism, and then use the cinchable loop so as to precisely andefficiently position the suture thread loop within the patient. Becausethe ligature assembly is engaged with the delivery mechanism, the twocan be operated or manipulated as a single unit by a surgeon or otheruser. By actuating the delivery mechanism, the user can safely cinch thesuture loop about the patient anatomy without causing harm or presentingundue risk to the patient. When a suture loop is positioned about theanatomical structure as desired, the operator can grasp or tug on anexposed proximal suture portion, and cut the suture thread, so as todecouple the cinched suture loop of the ligature assembly from theligature delivery system. Hence, from the time the ligature assembly isloaded onto the ligature delivery system, until the time the ligaturedelivery system is retracted from the patient, the engagement betweenthe ligature assembly and the ligature delivery system allows thephysician or operator to use the combination as a single unit in asimple, efficient, and effective manner. In this way, the combination ofthe ligature snare with the ligature delivery system provides asignificant improvement to existing snare technology. The deliverysystem can be withdrawn from the patient upon completion of theprocedure and the applied suture loop or closure means then operates toligate the anatomical structure.

In one aspect, embodiments of the present invention encompass ligaturedelivery systems for use with a left atrial appendage ligature assembly.Exemplary ligature delivery systems include a thread delivery mechanismhaving a cinchable loop that receives a thread of the ligature assemblyand that rotates axially about a central longitudinal axis between afirst configuration whereby the thread is shielded from a left atrialappendage of a patient and a second configuration whereby the thread canbe released onto the left atrial appendage. Ligature delivery systemsmay also include a delivery control mechanism that cinches the cinchableloop about the left atrial appendage and that switches the cinchableloop between the first and second configurations. Ligature deliverysystems may also include a support mechanism having a first engagementassembly that receives a carrier of the ligature assembly, and a secondengagement assembly coupled with the delivery control mechanism.Ligature delivery systems may also include a deflector mechanism thatpivots relative to the support mechanism and that is coupled with theloop. Ligature delivery systems may further include a deflection controlmechanism having an actuation assembly and a linkage assembly. Thelinkage assembly can be coupled with the actuation assembly and thedeflector mechanism, such that movement of the actuation assemblyrelative to the support mechanism causes the deflector body and loop topivot relative to the support mechanism. In some instances, thecinchable loop includes a flexible cylinder having a longitudinallyextending slot that receives the thread. In some instances, thecinchable loop includes a first section that translates longitudinallyrelative to a first guide of the deflector mechanism, and a secondsection that is translationally fixed relative to a second guide of thedeflector mechanism. In some instances, the delivery control mechanismeffects coordinated axial rotation between a first end portion of thedelivery mechanism and a second end portion of the delivery mechanism,and the first and second end portions border or bound a central portionof the loop. In some instances, the delivery control mechanism includesa gearbox assembly in operative association with the first and secondend portions. Operation of the gearbox can affect or cause thecoordinated axial rotation. In some instances, the delivery controlmechanism includes a first rotary drive coupled with a first section ofthe cinchable loop and a second rotary drive coupled with a secondsection of the cinchable loop, such that torque applied to either driveis transmitted between the first and second drives, and operates torotate the cinchable loop. In some instances, the delivery controlmechanism includes a first rotary drive coupled with a first section ofthe cinchable loop and a second rotary drive coupled with a secondsection of the cinchable loop, such that rotation of the first rotarydrive drives counter-rotation of the second rotary drive, and therotating drives coordinate to switch the cinchable loop from the firstconfiguration to the second configuration. In some instances, the secondengagement assembly includes a first lumen and a second lumen. In somecases the delivery control mechanism includes a first rotary drivedisposed within the first lumen of the second engagement assembly. Insome cases the first rotary drive is coupled with a first section of thecinchable loop. In some cases the delivery control mechanism includes asecond rotary drive disposed within the second lumen of the secondengagement assembly. In some cases the second rotary drive is coupledwith a second section of the cinchable loop. The first rotary drive canbe rotatable and translatable within the first lumen, and the secondrotary drive can be rotatable within the second lumen. In some cases thesecond rotary drive can translate within the second lumen. In some casesthe second rotary drive does not translate within the second lumen.

In another aspect, embodiments of the present invention encompassmethods for delivering a ligature loop to a left atrial appendage of apatient. Exemplary methods may include placing a ligature loop of aligature assembly about the left atrial appendage while the ligatureloop is engaged with a cinchable loop of a ligature delivery system.Methods may also include rotating the cinchable loop from a firstconfiguration, where the ligature loop is shielded from the left atrialappendage by the cinchable loop, to a second configuration, where theligature loop can be deployed to the left atrial appendage. The rotationcan be performed while the ligature loop and the cinchable loop encirclethe left atrial appendage. Methods can also include deploying theligature loop from the cinchable loop onto the left atrial appendage. Insome instances, methods include cinching the cinchable loop about theleft atrial appendage prior to rotating the cinchable loop to deploy theligature loop. In some instances, the cinchable loop includes a groove,and the ligature loop is engaged with the groove when the cinchable loopis in the first configuration, and is deployed from the groove when thecinchable loop is in the second configuration. Hence, methods mayinvolve engaging the ligature loop with the groove when the cinchableloop is in the first configuration, and deploying the ligature loop fromthe groove to the left atrial appendage when the cinchable loop is inthe second configuration. In some instances, the ligature assemblyincludes a carrier tube, the ligature delivery system includes a supportmechanism coupled with the cinchable loop, and the carrier tube isengaged with the support mechanism when the ligature loop is placedabout the left atrial appendage. Hence, methods may include engaging acarrier tube of a ligature assembly with a support mechanism of theligature delivery assembly. In some instances, the ligature assemblyincludes a knot or a ratchet mechanism. In some instances, a ligatureassembly may be provided as a band or loop. In some instances, methodsmay include securing the left atrial appendage with a grasping mechanismprior to placing the ligature loop about the left atrial appendage. Insome instances, methods may include advancing the ligature loop over thegrasping mechanism prior to rotating the cinchable loop.

In still another aspect, embodiments of the present invention encompassligature delivery systems which can be used with any of a variety ofleft atrial appendage closure mechanisms or other anatomical structureclosure mechanisms or means. Exemplary ligature delivery systems includea delivery mechanism having a cinchable loop that engages the closuremechanism and that rotates axially about a central longitudinal axisbetween a first configuration, where the closure mechanism is shieldedfrom an anatomical structure such as a left atrial appendage or cecalappendix of a patient, and a second configuration, where the closuremechanism can be released onto the anatomical structure. Systems mayalso include a delivery control mechanism that cinches the cinchableloop about the anatomical structure and that switches the cinchable loopbetween the first and second configurations. In some instances, thecinchable loop includes a groove that engages the closure mechanism whenthe cinchable loop is in the first configuration. In some instances, thedelivery control mechanism includes a first rotary drive coupled with afirst portion of the cinchable loop and a second rotary drive coupledwith a second portion of the cinchable loop. In some instances, systemsinclude a support mechanism having a recess that receives a proximaltail portion of the closure mechanism.

The terms “invention,” “the invention,” “this invention” and “thepresent invention” used in this patent are intended to refer broadly toall of the subject matter of this patent and the patent claims below.Statements containing these terms should be understood not to limit thesubject matter described herein or to limit the meaning or scope of thepatent claims below. Embodiments of the invention covered by this patentare defined by the claims below, not this Summary. This Summary is ahigh-level overview of various aspects of the invention and introducessome of the concepts that are further described in the DetailedDescription section below. This Summary is not intended to identify keyor essential features of the claimed subject matter, nor is it intendedto be used in isolation to determine the scope of the claimed subjectmatter. The subject matter should be understood by reference toappropriate portions of the entire specification of this patent, any orall drawings and each claim.

The above described and many other features and attendant advantages ofembodiments of the present invention will become apparent and furtherunderstood by reference to the following detailed description whenconsidered in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 depicts aspects of ligature delivery systems and methodsaccording to embodiments of the present invention.

FIGS. 2A, 2B, and 2C illustrate features of ligature assembliesaccording to embodiments of the present invention.

FIGS. 3, 3A, and 3B illustrate aspects of ligature delivery systems andmethods according to embodiments of the present invention.

FIGS. 4A to 4G show features of ligature delivery systems and methodsaccording to embodiments of the present invention.

FIG. 5 depicts aspects of ligature delivery systems and methodsaccording to embodiments of the present invention.

FIG. 6 depicts aspects of ligature delivery systems and methodsaccording to embodiments of the present invention.

FIGS. 7A to 7D illustrate features of ligature delivery systems andmethods according to embodiments of the present invention.

FIGS. 8A to 8J show aspects of ligature delivery systems and methodsaccording to embodiments of the present invention.

FIGS. 9A, 9B, and 9C depict features of ligature delivery systems andmethods according to embodiments of the present invention.

FIGS. 10A, 10B, and 10C show aspects of ligature delivery systems andmethods according to embodiments of the present invention.

FIG. 11 illustrates aspects of ligature delivery systems and methodsaccording to embodiments of the present invention.

FIGS. 12, 12A-1, 12A-2, and 12A-3 show aspects of ligature deliverysystems and methods according to embodiments of the present invention.

FIGS. 13A and 13B illustrate features of ligature delivery systems andmethods according to embodiments of the present invention.

FIG. 14 depicts aspects of ligature delivery methods according toembodiments of the present invention.

FIG. 15 depicts aspects of ligature delivery systems and methodsaccording to embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The subject matter of embodiments of the present invention is describedhere with specificity to meet statutory requirements, but thisdescription is not necessarily intended to limit the scope of theclaims. The claimed subject matter may be embodied in other ways, mayinclude different elements or steps, and may be used in conjunction withother existing or future technologies. This description should not beinterpreted as implying any particular order or arrangement among orbetween various steps or elements except when the order of individualsteps or arrangement of elements is explicitly described.

Embodiments of the present devices provide delivery systems and methodsfor applying ligatures or sutures to anatomical features of a patient.In some cases, delivery systems and methods can be used withpre-fabricated ligature assembly or pre-knotted suture thread loop. Forexample, a ligature assembly or snare apparatus may include a suture orthread that is tied with a one-way knot or hangman's noose, or that isotherwise configured with a one-way control mechanism such as a ratchet.The ligature assembly may include an elongate proximal tail, optionallydisposed within a carrier such as a stiff cylindrical tube. In someinstances, the proximal tail portion may be glued or otherwise affixedto a proximal portion of the carrier tube. Relatedly, the proximalportion of the carrier tube may have a score mark or other means bywhich the carrier tube can be easily or neatly broken apart, so as toprovide a proximal frangible portion and a more distal main body tube.In some instances, the score mark or breakable feature may be locatedapproximately one to two inches from the proximal end of the tube orcarrier. In use, the operator or surgeon may break off the proximalfrangible portion, and proximally retract or pull the frangible portionrelative to the main body tube. The knot or ratchet mechanism may beheld by a distal portion of the main body tube, such that as theoperator draws the proximal tail thread portion away from the main bodytube, the knot or ratchet remains snug against the distal carrier tubeportion as a looped portion of the thread distal to the knot becomescinched. In this way, the surgeon or user can apply opposing forces tothe thread knot and the proximal thread tail, so as to tighten thethread loop about an anatomical feature such as the left atrialappendage. Typically, the ligature assembly is provided as a single-usedevice.

Ligature delivery device systems and methods disclosed herein can beused with such ligature assemblies so as to provide an efficient andeffective approach for delivering looped suture thread to anatomicalfeatures of the patient. Such techniques allow the user or surgeon toeasily maneuver the distal thread loop about the patient's anatomy, andto control the placement of the distal thread loop as desired. What ismore, the present systems and methods may allow the surgeon or operatorto firmly cinch the thread loop about the patient's anatomy, withoutcutting into the patient's tissue. Hence, for example, the presenttechniques are well suited for use in a minimally invasive approach.

Embodiments of the present invention provide systems and methods forperforming epicardial closure of the left atrial appendage. Such systemsand methods can be used through any desired surgical access modality,including without limitation sternotomy, thoracotomy, and otherprocedures as discussed elsewhere herein.

Exemplary systems may include a grasping means or suction member thatcan be used to adhere to tissue and extend the appendage, so that aclosure means or occlusive device can be delivered to the appendagebase. Exemplary embodiments provide mechanically simple, user friendlydevices, which can be used to apply any of a variety of ligatureassemblies or closure means to patient tissue, which are easy to loadand reload with such ligature assemblies, and which can be used toefficiently deliver a ligature suture to the tissue (e.g. base of leftatrial appendage) while as the same time protecting the tissue frompotential cutting effects that may otherwise occur when tightening aligature thread about the tissue.

Turning now to the drawings, FIG. 1 illustrates aspects of an exemplaryligature delivery system 100 according to embodiments of the presentinvention. As shown here, the delivery system 100 includes a suturecarrier, guiding mechanism, or thread delivery mechanism 110 disposedtoward a distal portion of the system, and a handle mechanism 120disposed toward a proximal portion of the system. Delivery system 100also includes a main body or support mechanism 130, a deflection controlmechanism 140, a deflector mechanism 170, and a delivery controlmechanism 150 which may include a knob assembly. In some instances, thehandle mechanism may be integral to and part of the support mechanism130. As further described herein, a surgeon or operator can use deliverysystem 100 to administer or deliver a ligature thread or closing meansto an anatomical feature of a patient. For example, the delivery systemcan be loaded with a ligature assembly (see e.g. FIGS. 2A and 2B), suchthat a ligature thread loop of the ligature assembly is disposed aboutor received by a loop portion or cinchable loop 112 of the threaddelivery mechanism 110, and a knot pusher tube of the ligature assemblyis coupled with or received by the with the support mechanism or mainbody 130. The operator can then maneuver the ligature thread loop, byusing the deflection control mechanism 140 to deflect the suture carrierloop portion 112, as indicated by the A arrows. The operator can alsoexpand and contract the ligature thread loop, by using the deliverycontrol mechanism 150 to extend and retract one side of the suturecarrier loop portion 112 (to which the thread loop is engaged), asindicated by the B arrows. As discussed elsewhere herein, once theligature thread is positioned as desired, the operator can then deploythe ligature thread to the intended anatomical target by actuating thedelivery control mechanism 150, which in turn rotates the suture carrieror thread delivery mechanism 110. In this way, the suture carrier 110can operate as a guiding mechanism or delivery means for the ligaturethread. In some instances, the delivery system may also include anejector mechanism having an ejector handle 160. In some instances, aligature delivery system may be provided as a disposable single-patientuse product, such that the system may be used to apply several ligaturesor sutures to an individual patient during the course of a surgicalprocedure, and thereafter discarded. In some instances, the applicatormechanism can be triggered outside of the patient. Activation of thedelivery mechanism may act to cinch a lasso or compress a self-lockingclip, for example.

Ligature Assemblies

FIGS. 2A and 2B illustrate aspects of an exemplary ligature assembly 200according to embodiments of the present invention. In some cases, aligature assembly may be referred to as a ligating loop or a surgicalsnare. As depicted here, the ligature assembly 200 includes an elongatetubular shaft or knot pusher 210 having a lumen 212 therein, and aligature thread or closure means or mechanism 220 disposed at leastpartially within the lumen of the tubular shaft or carrier 210. In someinstances, a ligature assembly can be provided as a left atrialappendage ligature assembly. The ligature thread 220 can be pre-formedor pre-tied in such a way so as to present a knot 222 and a loop portion224. Generally, the knot 222 is disposed toward a distal portion 221 ofthe thread 220, and a proximal portion of the thread extends within theshaft lumen 212. In some instances, the tubular shaft may include adetachable or frangible proximal portion 214, and a proximal portion ofthe thread is attached with the detachable portion 214. For example, theproximal portion of the thread may be glued to the detachable portion214. As shown here, the tubular shaft 210 may include a score line 216,and the tubular shaft can be broken along the score line 216 so as toseparate the frangible portion 214 from a central portion or main body218 of the shaft 210. For example, the surgeon or operator may bend thepush tube 10 so that the frangible portion 214 cracks off, away from themain body 218. Once severed, the frangible portion 214 can be used topull the proximal thread tail out of the carrier tube, via a proximalend of the main body 218, thus tightening or cinching the ligature loop224. Typically, the thread or occlusive device 220 extends distally outof the shaft 210, for example through an aperture 217 of a tapereddistal portion 219 of the shaft.

According to some embodiments, the knot 222 is provided as a slip knot,sliding knot, running knot, or the like. For example, as the user oroperator pulls the frangible portion 214, and as the distal portion ofthe main body 218 holds the knot 222 in place, the knot 222 can allow aportion 225 of the thread sliding therethrough to move lengthwise freelyin one direction of pull (e.g. proximally toward the tube) as indicatedby arrow A, while preventing or inhibiting the portion 225 from slidinglengthwise in the opposite direction of pull indicated by arrow B. Inthis way, the knot 222 can perform as a non-return knot. A knot 222 maybe provided as a simple knot or a complex knot. Suitable knotconfigurations may also include laparoscopic knots, endoscopic knots,intracorporal knots, extracorporal knots, intraabdominal knots, surgicalknots, and the like. In some instances, a ligature assembly may includea knotted thread or suture having a distal loop portion and a proximaltail portion, without a carrier or push tube. As further discussedelsewhere herein, the ligature delivery systems and methods provided inthe instant disclosure allow a surgeon or operator to constrict the loop224 about the patient's anatomy without having the sliding portion 225cut into or form a groove in the patient's tissue.

FIG. 2C illustrates another exemplary ligature assembly or snare 200 caccording to embodiments of the present invention. As shown here, theligature assembly includes a proximal tail portion 210 c and a distalportion 220 c which can be formed into a loop, for example by passingthe proximal portion through a ratchet mechanism 230 c. In this way, thedistal portion can provide a ligature loop or closure means. The distalportion includes a series of projections 222 c which may include teeth,barbs, beads, or the like. Typically, the projections are shaped so thatthey can be easily pulled through the ratchet mechanism 230 c in onedirection as indicated by arrow A, and resist movement through theratchet mechanism 230 c in the opposing direction as indicated by arrowB. For example, the projection may be triangular in shape or have asloped surface. In this way, the coordinated operation between theprojections 222 c and the ratchet mechanism 230 c operate in a mannersimilar to that of a one-way or non-return knot. In some instances, theratchet mechanism 230 c may include a flexible pawl deforms when rigidprojections are passed along the ratchet. In some cases, the projectionsare flexible and deform when passed along a rigid pawl of the ratchet.Once the projection proceeds past the ratchet or pawl (in the directionindicated by arrow A), it is prevented or inhibited from returning inthe opposite manner (as indicated by arrow B). In this way, the loop orclosure mechanism can be cinched or constricted as desired to aparticular diameter or size, and when the projection is locked againstthe ratchet or pawl the loop cannot be expanded or uncinched.

In some cases, a ligature assembly includes a threadlike suture that canreside partially within a tube or carrier. In some case, the suture ispre-formed with a knot. Hence, when a looped distal end of the ligatureis positioned at a desired location about the LAA, the proximal portionof the ligature can be pulled or actuated, so as to tighten the loop,thus securing the knot. Some ligature assemblies may include a suturewhich extends from a distal end of the carrier in the form of a loop,having a sliding knot which secures itself when tightened. In somecases, ligature assemblies include a suture that is non-absorbable bythe patient's body. Embodiments of the present invention encompasssystems and methods for use in conjunction with such ligatureassemblies, for the delivery of a suture to the patient's LAA.

Commercially available ligature assemblies include Surgitie™ single useligating loops and ENDOLOOP® ligatures. Often, such pre-fabricated orpre-tied ligature assemblies are packaged so that proximal tail portionof the ligature thread is disposed within the carrier tube shaft, andthe knot and loop portions extend distally from or beyond the carriertube or pushrod. A proximal portion of the tube or pushrod can besnapped off, exposing the proximal tail of the ligature thread.Exemplary knots and ligature assemblies are described in European patentnumber EP 0477020 and German patent number DE 566173, and by Hage, Surg.Laparosc. Endosc. Percutan. Tech., February 18(1):1-7 (2008), thecontents of which are incorporated herein.

Exemplary ligature assemblies often include a tube or carrier, and aligature thread. In some cases, the tube or carrier can be fabricated ofnylon or another suitable material. The thread or suture can includeplain gut elements, synthetic polymers or copolymers, polymericfilaments, monofilament, polyester or other suitable materials, coatedconfigurations, braided configurations or threads, and the like. In someinstances, the diameter of the ligature thread may be between about 15and 20 thousandths of an inch. In some instances, other thread diametersmay be used. It is understood that the ligature delivery system mayinclude thread guides, slots, grooves, and the like, which are sized orconfigured to operate with any ligature thread diameter, cross-section,or configuration. Similarly, the ligature delivery system may includeknot or ratchet guides, pockets, stops, and the like, which are sized orconfigured to operate with any ligature thread knot or ratchet size orconfiguration.

In some instances, an exemplary system may include a closure deliverymeans that presents a semi-rigid profile which provides an elongateclamping surface. In some instances, the closure delivery means may alsoinclude or operate in coordination with a hypotube assembly that housesor receives portions of a closure means, such as a ligature. The closuremeans may be in the form of a loop, a snare, a lasso, a noose, or thelike. The closure means may also include a ligature or tie having a knotsuch as a one-way knot or slip knot. The system may also include atension force limiter that decouples the shaft from the ligature at apreset load, for example by using a spring.

In some embodiment, the ligature assembly or closure means may includean elastic or stretchable band or ligature loop that does not include aknot, ratchet, or proximal tail. Such a closure means or mechanism canbe wrapped in a generally circumferential manner about the cinchableloop of the ligature delivery system. In some cases, the band or loopmay be disposed at least partially in a groove or recess of thecinchable loop, or the band or loop may be engaged with a guide of thecinchable loop or be otherwise engaged with the cinchable loop, suchthat the band or loop resides upon the cinchable loop with the cinchableloop is in a first configuration (see e.g. FIG. 8A), and the band orloop is deployed or released from the cinchable loop to the targettissue when the cinchable loop is in a second configuration (see e.g.FIG. 8D). The cinchable loop can be converted from the firstconfiguration to the second configuration by, for example, rotating thecinchable tube loop about a central longitudinal axis of the loop tube.In some cases, such a band or loop may have a cross-section diameterwithin a range from about 0.10 inch to about 0.25 inch. In such cases,the delivered band or loop is not held in place upon the target anatomydue to a one way knot or ratchet mechanism, but rather is held in placeby the elasticity of the band or loop itself. In some cases, such a bandor loop can be delivered to a target anatomy over a suction device orgrasping means (see e.g. FIG. 12).

In some instances, a surgical tie total loop circumference beyond thesnare tip can be about 9.3 inches. A loop circumference at the base ofan LAA can be about 4 inches. In many patients, the base of the LAA maybe about 5 inches in circumference. In some instances, the excess doublelength can be about 5 inches total. Such an excess of ligature lengthmay be difficult to manage if loose. In some situations, a surgeon oroperator may pull in about 2 to 3 inches before mounting in the snare. Aslack puller on a finger opposite the snare arm can allow a single pullhandle at the back to cinch up the snare and the snare tip could residein a nose scoop. The surgeon or operator may load the slack-pullingfinger as well.

The left atrial appendage (LAA) is a finger like muscular pouch which isconnected to and originates supralaterally from the left atrium of theheart. In some cases, the LAA has been referred to as the left auricularappendix, the auricula, or the left auricle. Left atrial appendageocclusion treatments can be an effective means of preventingcomplications, such as stroke, which may result from atrial fibrillationor eliminate one possible source of aberrant electrical circuits thatmay originate in the appendage and contribute to atrial fibrillation.FIG. 3 illustrates aspects of a delivery process whereby a ligaturethread can be applied to an anatomical feature of a patient. Forexample, as depicted here, a ligature delivery system 300, optionally incombination with a suction apparatus or grasping means 310, can be usedto deliver a ligature thread to a left atrial appendage (LAA) 320 of apatient's heart 330. Accordingly, the applied ligature thread can beused to isolate and occlude the LAA, for example during or as part of anatrial fibrillation treatment procedure. In this way, the appliedligature thread can help to prevent or inhibit negative effectsassociated with a thromboembolus of the LAA. Typically, the ligaturethread loop is applied around the base 322 of the LAA. In manyindividuals, the circumference at the base 322 of the LAA is within arange from about 4 to about 5 inches. The ligation technique can also beused during or as part of a mitral valve repair procedure. Exemplarygrasping means may include suction mechanisms, or other gripping orholding devices such as forceps, clamps, and the like. As shown here,the grasping means 310 can include an elongate handle 312 coupled with asuction cup 314 via a connection 316. In some cases, the handle 312 maybe coupled with the suction cup 314 via a jointed connection, such as aball joint or a hinge joint, or via a deflectable hinge connection orthe like. The grasping or suction means 310 may also be integrated intothe ligature delivery system so that it enters the patient's body at thesame location.

Loading the Delivery System with a Ligature Assembly

As indicated above, a typical ligature assembly includes a pre-knottedthread having a proximal tail and a distal loop, and a tube carrierdisposed about at least a portion of the proximal tail. FIG. 3A depictsa delivery system 300 a loaded with a ligature assembly 320 a accordingto embodiments of the present invention. As shown here, the ligatureassembly 320 a includes a knot pusher or carrier tube 322 a and aligature thread 330 a having a knot or one way locking mechanism 332 a,a distal loop portion 334 a, and a proximal tail portion 336 a disposedat least partially within the carrier tube 322 a. The delivery system300 a includes a support mechanism 340 a having an engagement assembly342 a such as a recess or groove that is configured to receive andreleasably attach with the ligature assembly carrier tube 322 a. Forexample, the carrier tube can be snapped or clipped into place withinthe recess or slot of the support mechanism 340 a. The ligature threaddistal loop portion 334 a can be threaded or routed within or along agroove 352 a of a distal deflector body 350 a, and also within or alonga groove 362 a of a thread delivery mechanism or closure delivery means360 a. According to some embodiments, a cinchable loop of the threaddelivery mechanism 360 a may include a flexible cylinder having alongitudinally extending slot 362 a that receives the ligature thread.

FIG. 3B shows a side view of a proximal portion of the delivery system300 a. As shown here, a proximal tail portion 336 a of the ligaturethread extends proximally from the delivery system handle 370 a. In use,the proximal tail portion 336 a can be wound about a thread holdermechanism 382 a of a delivery control mechanism 380 a. For example, thesurgeon can crack a scored portion of a carrier tube so as to separate afrangible portion from a main body portion, wrap the distal thread loopabout the slot 362 a of the torqueable carrier tube loop, and then holdthe frangible tube portion (as shown in FIG. 2A or 10A) to draw taut theproximal thread potion, and thereafter wind the proximal tail threadportion 336 a about the thread holder 382 a grooves. In this way, theproximal thread portion can be fixed to the knob. In some instances, theknob or thread holder mechanism 382 a may include grooves, wedgecut-outs, helical or circular rings or slots, and the like. The operatormay wrap the proximal thread portion 336 a about the holder mechanism382 a in multiple windings, optionally with thread guide assistanceprovided by pin 383 a (as illustrated in FIGS. 7A and 7B). Hence, one ormore thread wrappings or windings can be inserted into one or moregrooves or groove sections. Relatedly, thread wrappings or windings canbe stacked one upon another. What is more, thread wrappings or windingscan be drawn taut relative to the grooves or rings, so as to drive orwedge the threads deeper into the grooves or between rings, so as tolock or fix the proximal thread portion 336 a in place, relative to theknob and/or rotary drive. As further explained elsewhere herein, whenthe proximal tail portion 336 a is wound about or otherwise coupled withor fixed to the thread holder mechanism 382 a or knob 381 a, thedelivery control mechanism 380 a can be retracted proximally or axiallytranslated in the direction indicated by arrow A relative to the handle370 a, so as to simultaneously contract or cinch both the suture carrierloop and the suture loop (which is mounted on the suture carrier loop).For example, the suture carrier cinchable loop and the thread loop maybe constricted or tightened at the same rate. In this way, the cinchablesuture carrier loop can be tightened about an anatomical feature whilethe loop thread remains positioned within a slot or groove of thecinchable loop. Further, the knob 381 can be rotated relative to thehandle or support mechanism so as to deliver or adjust a cinchablesuture loop, as further discussed elsewhere herein.

In some instances, a physician or operator may use a semi-automatedmechanism for loading (and reloading) a suture or closure means onto thecinchable loop. In some instances, a physician or operator may use ahand held instrument for loading (and reloading) a suture or closuremeans onto the cinchable loop.

Deflection of the Guiding Mechanism Loop Portion

As noted above, the deflection control mechanism can be used to deflectthe loop portion of the guiding or thread delivery mechanism. FIG. 4Ashows a partial cross-section view of an exemplary ligature deliverysystem 400 according to embodiments of the present invention. Asdepicted here, a deflection assembly 405 may include a distal deflectorbody 405 a coupled with a main body or support mechanism 430 of thedelivery system 400. In use, the operator can actuate a lever of adeflection control mechanism, which in turn translates a deflectioncontrol linkage 407 coupled between the lever (not shown) and the distaldeflector body 405 a. As shown here, linkage 407 maybe at leastpartially disposed within or otherwise in operational association with aguide or lumen 438 of the support mechanism 430.

Thus, for example, by actuating the lever so as to retract the linkage407 proximally as indicated by arrow A1, the linkage 407 pulls a pin 405b of the deflector body in a proximal direction and the distal deflectorbody 405 a rotates relative to a main body pivot 432 as indicated byarrow A2. Consequently, a guiding mechanism loop portion 412 deflectsrelative to the main body 405 a as indicated by arrow A3. Relatedly, byactuating the lever so as to advance the linkage 407 distally asindicated by arrow B1, the linkage 407 pushes the pin 405 b of thedeflector body in a distal direction and the distal deflector body 405 arotates relative to the main body pivot 432 as indicated by arrow B2.Consequently, the guiding mechanism loop portion 412 deflects relativeto the main body 405 a as indicated by arrow B3. In this way, a user canflip the main body 405 a, and a cinchable loop 442 coupled thereto, inan up-down fashion to provide any desired degree of pitch. Typically,the loop is deflected such that a plane defined by the cinchable loop(and hence a corresponding plane defined by the suture loop portion) istipped or angled relative to a central longitudinal axis defined by thesupport mechanism. As shown here, the main body pivot or hinge 432 isshaped as a cylinder, although it is understood that the main body pivot432 may optionally be shaped as a sphere, so as to provide a ball joint.The deflector mechanism or body 405 a includes a corresponding recess orgroove 406 a that receives the pivot or hinge 432. Any suitable hinge orpivot mechanism may be used to couple the support mechanism 430 with thedeflector body 405 a. In some cases, the support mechanism and deflectorbody may be coupled via a living hinge, such that the support mechanismand the deflector body are both part of a single molded or fabricatedelement, with a thin or flexible connection therebetween.

FIG. 4A also illustrates a ligature assembly 410 a engaged with thedelivery system 400. As shown here, the ligature assembly 410 a includesa carrier tube 412 a having a lumen 414 a, and a ligature thread 416 ahaving a knot 418 a. A proximal tail 419 a of the thread is disposedwithin the lumen 414 a, and the knot 418 a is disposed distal to adistal end or port of the tube 412 a.

FIGS. 4B, 4C, and 4D depict the deflection assembly 405 in a first orforward deflection configuration. As shown here, a deflection assemblylever 406 of an actuation assembly 409 is moved distal relative to thedelivery system handle 420 as indicated by arrow A1, and in acorresponding manner, the deflection assembly linkage 407 is also moveddistal relative to the main body 430 as indicated by arrow A2, such thatthe deflector mechanism or distal deflector body 405 a and cinchableloop 442 are pivoted in a downward direction as indicated by arrow A3.The actuation assembly 409 may include an arch or support 409 a havingmultiple flexible fingers 409 b with protruding beads 409 c, which canreleasably engage and hold lever 406 at any of a series of discreteangled orientations relative to the support mechanism. Hence, as thelever 406 is pivoted distally as indicated by arrow A1, the leverangularly rotates about a pivot mechanism 406 a, and a slot 406 b of thelever moves distally relative to the support 409 a. A hole or recess 406c of the lever sequentially receives or engages the individual fingerprotrusions 409 c as the lever moves, with the protrusions 409 c poppinginto and out of the recess 406 c. The engagement between the fingerprotrusions 409 c and the lever recess 406 c provide physicalinterference so that the lever can be moved incrementally at discreteangular positions relative to the support mechanism 430.

FIGS. 4E, 4F, and 4G depict the deflection assembly 405 in a second orreverse deflection configuration. As shown here, a deflection assemblylever 406 of the actuation assembly 409 is moved proximal relative tothe delivery system handle 420 as indicated by arrow A1, and in acorresponding manner, the deflection assembly linkage 407 is also movedproximal relative to the main body 430 as indicated by arrow A2, suchthat distal deflector body 405 a and cinchable loop 442 are pivoted inan upward direction as indicated by arrow A3. In some instances, thesupport mechanism 430 or handle 420 includes a series of stops orengagement features 422 which can engage a corresponding recess orengagement feature 408 of the lever 406, such that the linkage 407 canbe incrementally translated or adjusted relative to the supportmechanism, thereby provided discrete pitch adjustments for the cinchableloop.

Lateral Movement of the Guiding Mechanism Loop Portion

As depicted in FIG. 5, a ligature delivery system 500 may include adeflection control mechanism 510 that, in addition to or in place of apitch control assembly as illustrated in FIGS. 4A to 4G, also includes ayaw control assembly 520. For example, the yaw control assembly mayinclude a linkage or push-pull rod 522 coupled with the deflectormechanism 530, such that proximal and distal translational movement ofthe linkage 522 relative to the support mechanism 540 as indicated byarrow A, operates to deflect or pivot the deflector mechanism 530 in aside-to-side fashion as indicated by arrow B. To facilitate suchpivoting yaw movements, the ligature delivery system may include a hingeor pivot (e.g. such as a ball joint) disposed between and connecting thesupport mechanism with the deflector mechanism. A similar hinge or pivot(e.g. such as a ball joint) can be disposed between the pitch controllinkage 560 and the deflector mechanism. In some cases, the yaw controlassembly may include two parallel linkages or push-pull rods. So, forexample, a first linkage may advance distally while a second linkageretracts proximally, the coordinated action between these two linkagesoperates to rotate the deflector mechanism (and hence the cinchable loop550) in a yaw direction as indicated by arrow B. Alternately, if aparticular yawed, or sideways disposed position is desired for thecinchable loop, the distal assembly may have a bend permanently designedinto its shape, and the ligature delivery system may not include controllinkages and hinges or ball joints as described above. In yet anotherembodiment, the deflector body or mechanism may be moveable as describedabove, for example with control linkages and hinges or ball joints, andthe hinge or ball joint connection may include an offset or angularalignment orientation so as to dispose the deflector body or mechanismto one side or up or down in a nominally offset position from the longaxis of the main delivery device body or support mechanism.

Guiding the Ligature Loop to the Anatomical Feature

In use, the distal portion of a ligature delivery system 600 can bedelivered or introduced through a patient access location 605 of apatient P, in the direction indicated by arrow A, as illustrated by FIG.6. In some cases, the access location 605 may be provided by athoracotomy in the left side of the patient's body. For example, theaccess location 605 may be provided by a port access between the ribs onthe left side of the patient's chest. By actuating one or more levers orcontrol sliders 622 of a deflection control mechanism 620, and/or byrotating the support mechanism 640 about its central longitudinal axis,the operator can adjust the orientation of the cinchable loop 630 to anydesired degree of pitch, yaw, or roll, thus aligning the loop for facileplacement about the anatomical structure (e.g. left atrial appendage orLAA). In some instances, the device may be configured to pivotthroughout a pitch range of 180 degrees. Hence, the maneuverability ofthe ligature delivery system allows the surgeon or operator to align aplane defined by the ligature thread loop in any desired orientation.For example, the plane defined by the ligature thread loop can bealigned with a plane defined by the base of the left atrial appendage,thus promoting facile application of the ligature snare to the leftatrial appendage. In this way, the operator or surgeon can adjust theplane of the suture loop to any desired orientation related to thepatient's anatomy (e.g. the base of the left atrial appendage). Asfurther discussed elsewhere herein, the ligature delivery assembly mayinclude or be used in cooperation with a tissue grasping assembly suchas a suction cone assembly, a forceps assembly, or the like, which canbe used to positionally manipulate the patient tissue relative to theligature thread loop or cinchable loop carrier.

In some cases, a patient administration modality may be achieved througha port access, a sternotomy access, a thoracotomy access, a subxyphoidaccess, a subcostal access, a transdiaphragmatic access, or the like. Insome instances, the support mechanism 640 may be constructed to includea curved configuration or portion, which may provide additional benefitsduring a subxyphoid access procedure, for example. In some instances,portions of the system such as a support mechanism may be manufacturedwith a pre-formed curve. In some instances, portion of the system suchas the support mechanism may be manufactured to include a flexible orbendable section. In some cases, access may be achieved with theligature delivery system 600 during a concomitant surgical proceduresuch as an atrial fibrillation ablation procedure, a bypass surgeryprocedure, a valve surgery procedure, or the like.

As shown here, the support mechanism 640 can engage with a carrier tube660 of a ligature assembly. Optionally, where a ligature assembly doesnot include a carrier tube, the proximal tail portion of the ligaturethread can be placed along or within an engagement member or guide 642of the support mechanism. The engagement member or guide 642 can besized or configured to accommodate or receive carrier tubes of anysuitable length, diameter, cross-section shape, or configuration.Similarly, the engagement member or guide 642 can be sized or configuredto accommodate or receive ligature threads of any suitable length,diameter, cross-section shape, or configuration.

Sizing the Ligature Loop to the Anatomical Feature

When the suture thread loop and the cinchable loop of the threaddelivery mechanism are positioned as desired, the delivery system can beactuated so as to simultaneously contract or cinch the deliverymechanism and suture loops about an anatomical feature. For example, asdepicted in FIGS. 7A to 7E, the delivery control mechanism 700 mayinclude a first rotary drive or translating suture carrier support 710and a second rotary drive or fixed suture carrier support 720. In someinstances the first rotary drive 710 is disposed within a first lumen orengagement mechanism of the support mechanism 760. In some cases thesecond rotary drive 720 is disposed within a second lumen or engagementmechanism of the support mechanism. Hence, the support mechanism may beconsidered to include an engagement assembly (e.g. which includes thefirst and second lumens) that couples with a delivery control mechanism.The translating rotary drive 710 includes a proximal portion 712 coupledwith a control knob 730 that can be retracted proximally out of thehandle 740 as indicated by arrow A. The translating rotary drive 710also includes a distal portion 714 coupled with a translating portion752 of the thread delivery mechanism 750 that can be retractedproximally into the support mechanism 760. As shown here, a proximaltail portion 772 of a ligature thread 770 can be fixed relative to thecontrol knob 730, and thus drawn proximally when the knob is drawnproximally. A broken-off frangible portion (not shown) of the carriertube may be dangling from a proximal end of the thread tail 722.Alternatively, the frangible portion may be pushed into a wedge shapedgroove in the control knob 730, the slack in the suture being taken upby the lengthwise position of the frangible portion in the groove.Hence, when knob 730 is drawn proximally, the first rotary drive 710 isdrawn proximally as indicated by arrows A, the thread delivery mechanismtranslating portion 752 is drawn proximally as indicated by arrow B,thus cinching the loop 750, and a ligature thread loop translatingportion 772 (which is connected with the knob via the thread proximaltail) is also drawn proximally as indicated by arrow C, and through thesuture knot, thus cinching the ligature loop. As shown here, astranslating portion 772 of the ligature thread is drawn proximally, itcontinually exits a groove 755 of the thread delivery mechanism 750 at amoving peel-off point 756. In this way, the thread delivery mechanism750 moves in conjunction with the ligature thread 770, such that bothelements can be simultaneously cinched about a desired anatomicalfeature. As the translating portion 759 of the cinchable loop is drawnacross the patient tissue, the cinchable loop operates to protect thetissue which would otherwise be in contact with the translating portion772 of the ligature thread. More generally, the cinchable loop operatesto protect or shield the patient tissue from the suture thread, untilsuch a time that the suture thread is delivered to the patient tissue(e.g. by rotating the cinchable loop, as described elsewhere herein).The non-translating rotary drive 720 includes a distal portion 722coupled with a similarly non-translating portion 754 of the threaddelivery mechanism 750, in that the rotary drive 720 and thenon-translating portion 754 do not translate relative to the supportmechanism. As described elsewhere herein, a push-pull rod or linkage 780can operate to deflect a deflector mechanism 790. In some instances, aknob 730 may include an orientation indicator 732, so that an operatoror user can visualize the rotational orientation of the knob, and thusbe aware of the corresponding rotational orientation of the rotarydrives and the cinchable loop. In some cases, the orientation indicator732 may represent the position of the carrier tube groove, the positionof the thread disposed within the carrier tube groove, the position ofthe groove in the translating portion 752 of the delivery mechanism 750,or the position of the thread in the translating portion 752 (e.g.relative to the central longitudinal axis of the carrier tube or firstrotary drive). In this way, the surgeon may know whether or not thethread delivery mechanism is in a configuration suitable for deliveringthe ligature thread to the anatomical structure. In an additional butrelated embodiment, the delivery system may be designed such that whenthe cinchable carrier loop 750 is cinched onto the target tissue, thesuture loop moves with the cinchable loop 750, thus protecting thetissue, but the suture loop is not actually cinched tight until afterthe carrier loop 750 is tight. This can be accomplished by pulling bothsides of the carrier loop 750 into the support mechanism 760simultaneously, for example by drawing the first rotary drive 710 andthe second rotary drive 720 in a proximal direction, and also moving theligature assembly carrier tube and the ligature knot in a proximaldirection, thus allowing the suture loop to also move proximally. Whenthe carrier loop 750 is sufficiently tight, the suture loop can betightened, for example by moving the ligature assembly carrier tube orknot pusher in a distal direction so as to advance the knot in a distaldirection, while optionally pulling or retracting a frangible portion ofthe ligature assembly in a proximal direction. In this way, theadvancing knot, with the carrier tube backing it up, can approach andcontact the tissue. The circumferential cinching force can betransferred from the carrier loop 750 to the suture, but because thishappens at the last moment, there is no slicing action against thetissue by the suture loop. The delivery system can then unload or deploythe suture and be removed.

Delivering the Ligature Loop to the Anatomical Feature

As depicted in FIGS. 7C and 7D, the thread disposed within the slot ofthe cinchable loop portion can be shielded from the ensnared anatomicalfeature. For example, as illustrated in the cross-section view of FIG.8A, the left atrial appendage (LAA) is encircled by a cinchable loop 810of a ligature delivery system. The cinchable loop can rotate about acentral longitudinal axis 812, as indicated by arrows A. In this way,the cinchable loop can switch between a first configuration where thethread 820 is shielded from the left atrial appendage, as shown in FIG.8A, and a second configuration where the thread 820 can be released ontothe base of the left atrial appendage, as shown in FIG. 8B. Similarly,as illustrated in the cross-section view of FIG. 8C, the left atrialappendage (LAA) is encircled by a cinchable loop 810 of a ligaturedelivery system. The cinchable loop can rotate about a centrallongitudinal axis 812, as indicated by arrows A. For example, the slot830 of the cinchable loop can be rotated toward the appendage by about10 to 15 degrees. It is understood that any suitable angular rotation ofthe cinchable loop may be performed so as to deliver the thread orsuture to the desired location. In this way, the cinchable loop canswitch between a first configuration where the thread 820 is shieldedfrom the left atrial appendage, as shown in FIG. 8C, and a secondconfiguration where the thread 820 can be released onto the base of theleft atrial appendage, as shown in FIG. 8D. Hence, in some cases thesuture may be facing outward away from the left atrial appendage as thecinchable loop is tightened. In other cases, the suture may be facingdownward toward the base of the left atrial appendage as the cinchableloop is tightened. It is therefore understood that the suture may befacing in any desired direction relative to the left atrial appendage asthe cinchable loop is maneuvered and/or constricted. Typically, thegroove or slot 830 will be oriented such that the left atrial appendageis shielded from the suture as the loop tightens, which can help toprotect the left atrial appendage (or other any other anatomicalstructure or tissue to which a ligature is applied) from being damagedas the ligature is tightened or constricted about the tissue. In someinstances, the applicator system may be configured to decouple theocclusive member from the applicator upon delivery of the occlusivemember so as to minimize potential for tissue trauma.

FIG. 8E depicts another thread delivery mechanism configurationaccording to embodiments of the present invention. As shown in thiscross-section view of a cinchable loop 800 e, the slot or groove 810 epresents an offset angle relative to radius R of the loop cylinder.Biasing the slot 810 e at a different angle, offset relative to thecenter of the carrier cylinder, may enable the effect of tightening thesuture to assist in the rotation of the suture carrier. For example, asshown here, tightening the suture thread loop 820 e within the groove asindicated by arrow A, may result in application of a rotational force tothe loop 800 e as indicated by arrow B. Relatedly, the biased slot mayit may assist in retaining the suture thread 820 e in the groove untilthe suture carrier or thread delivery mechanism has rotatedsignificantly inward. If there is sufficient traction between the tissueand the loop, however, the rotation indicated by arrow B may operate tomove the loop away from an intended target (e.g. the base of the leftatrial appendage), or to pull the tissue downward through the cinchableloop, placing the suture high on the anatomy (e.g. far away from thebase of the base of the left atrial appendage).

FIG. 8F depicts another thread delivery mechanism configurationaccording to embodiments of the present invention. As shown in thiscross-section view of a cinchable loop 800 f, the slot or groove 810 fpresents an offset angle relative to radius R of the loop cylinder.Biasing the slot 810 f at a different angle, offset relative to thecenter of the carrier cylinder, may enable the effect of tightening thesuture to assist in the rotation of the suture carrier. For example, asshown here, tightening the suture thread loop 820 f within the groove asindicated by arrow A, may result in application of a rotational force tothe loop 800 f as indicated by arrow B. Relatedly, the biased slot mayit may assist in retaining the suture thread 820 f in the groove untilthe suture carrier or thread delivery mechanism has rotatedsignificantly inward.

FIG. 8G depicts another thread delivery mechanism configurationaccording to embodiments of the present invention. As shown here, athread delivery mechanism may include a deeply recessed narrow groove810 g that is shaped to receive a band or ribbon suture thread 820 g ina radially aligned orientation.

FIG. 8H depicts another thread delivery mechanism configurationaccording to embodiments of the present invention. As shown here, athread delivery mechanism may include a shallowly recessed broad groove810 h that is shaped to receive a band or ribbon suture thread 820 h ina tangentially aligned orientation.

FIG. 8I depicts another thread delivery mechanism configurationaccording to embodiments of the present invention. As shown here, athread delivery mechanism may include an ovalized groove 810 i that isshaped to receive an ovalized suture thread 820 i.

Accordingly, embodiments of the present invention encompass any of avariety of slot or groove shapes or configurations, as well as variousthread shapes and sizes. As can be seen in FIGS. 8A to 8I, firm cinchingforce can be applied to a suture thread or other ligature filament, suchthat a portion of the thread loop is drawn through a knot withoutsliding against the patient's tissue. In this way, ligature thread loopscan be applied to the patient anatomy with a significantly reduced riskof cutting the tissue with the tightening thread. In some instances, aligature thread may have a thickness of about 15 to about 20 thousandthsof an inch. Embodiments of the present invention provide techniques fortightening such threads about patient tissue features, while protectingthe tissue from severing effects that the thread may otherwise have onthe tissue. For instance, where a ligature thread includes a one-wayknot with a distal loop, upon tightening of the thread, one portion ofthe loop remains fixed relative to the knot, and another portion of theloop slides through the knot. Use of the presently described systems andmethods allows the surgeon or user to translate the sliding loop portionthrough the knot, while placed under significant compressive forces,without having the sliding thread cut into or otherwise damage orcompromise the patient tissue. In some instances, a ligature deliverysystem is provided as a single-patient use device, whereby a surgeon oroperator can use the delivery system as desired to deliver one or moreligature threads to the patient anatomy. In some instances, a user oroperator can use the delivery system to apply multiple ligature loops toa single anatomical feature, thus for example spreading out or otherwisedistributing the compressive forces applied to the anatomical feature.

As depicted in FIG. 8J, in some instances a cinchable loop 800 j mayinclude a soft, flexible tube having an inner diameter (ID) and an outerdiameter (OD). In use, the cinchable loop rotates about a centrallongitudinal axis 810 j of the loop. According to some embodiments, theOD is about 3/16 inch, and the ID is about 1/16 inch. Other suitabledimensions can be used for the tube configuration. In some cases, acinchable loop may include a longitudinally extending rod or supportmember 820 j within the wall W of the tube, to help enhancetorqueability of the loop. The rod or support member 820 j can beflexible and stiff, and optionally may be glued in place within the tubewall. The rod or support member 820 j can be bendable, yet stiff so asto import additional torqueability to the tube. In some cases, the rodor support member may be placed within a longitudinally extending lumenor slit of the tube. In some cases, a cinchable loop may include aspring or helical member disposed within a wall of the tube, such thatthe spring or helical member helps the tube resist compressive forces,yet also imports torqueability to the tube while maintaining thebendability of the tube. As depicted here, the OD of the tube may beselected such that upon cinching of the cinchable loop, the loop or tubedoes not sever or otherwise compromise the patient tissue against whichit is moved or compressed. Alternately, the loop, either in a tube orrod form, may have incorporated within its wall or against its IDadditional structure such as a tubular braid or helical coils of polymeror metal that enhance torque transmission, without significant wind-up,and reduce kinking.

FIGS. 9A and 9B depict additional details of a ligature delivery system,and how actuation of a delivery control mechanism can operate to converta thread delivery mechanism from a first configuration where a ligaturethread is shielded from the tissue of an ensnared anatomical feature, toa second configuration where the ligature thread can be delivered to theanatomical feature. As shown here, the ligature delivery system 900includes a delivery control mechanism 910 having a first rotary drive920 and a second rotary drive 930. The first and second rotary drivesare coupled together via a gearbox assembly 940, such that torqueapplied to one rotary drive is transmitted to the other rotary drive.For example, the first and second rotary drives may be aligned in aparallel or co-linear fashion, each rotating about its own centrallongitudinal axis, in a direction opposite to the other. According tosome embodiments, the gearbox assembly 940 includes a first gear 942coupled with the first rotary drive 920, and a second gear 944 coupledwith the second rotary drive 930. Hence, the gearbox assembly mayinclude a dual-gear or multi-gear mechanism. In some cases, first gear942 may be integral with or part of the first rotary drive 920, andsecond gear may be integral with or part of the second rotary drive 930.In some cases, the first rotary drive 920 is axially slidable ortranslatable relative to first gear 942. In some cases, the secondrotary drive 930 is axially slidable or translatable relative to secondgear 944. In some cases, the second rotary drive 930 does not translateor move axially along the length of the support mechanism relative tothe second gear 944. A distal portion of the first rotary drive 920 iscoupled with or rotationally fixed relative to a first portion 952 of acinchable loop 950, and a distal portion of the second rotary drive 930is coupled with or rotationally fixed relative to a second portion 954of the cinchable loop 950. As shown here, the cinchable loop 950includes a groove or slot 956 that received a suture or ligature thread960. The cinchable loop first portion 952 may rotate within or relativeto a first guide or aperture 972 of a deflector mechanism 970, and thecinchable loop second portion 954 may rotate within or relative to asecond guide or aperture 974 of the deflector mechanism 970. As shown inthe enlarges perspective view of FIG. 9C, the first rotary drive 920 mayinclude a pin or protrusion 921 that engages or inserts into the threaddelivery mechanism slot 956. Similarly, the second rotary drive 930 mayinclude a pin or protrusion 931 that engages or inserts into the threaddelivery mechanism slot 956. Such pins, protrusions, tabs, or splines921, 931 can help to transfer torque from the rotary drives to thethread delivery mechanism when the rotary drives are rotated. In thisway, the cinchable loop can be simultaneously torqued or forciblyrotated from two opposing sides of the loop. As described elsewhereherein, the rotary shafts 920, 930 can be used to rotate the suturecarrier end portions 952, 954 in opposing directions, so as to positionthe slot 956 and the suture thread carried by the slot 956 to thedesired orientation for depositing the thread loop about the base of theleft atrial appendage. Hence, the cinchable loop 950 may operate as atorqueable suture carrier, that can be rolled or rotated so as todeliver a suture or ligature thread to an anatomical site, for exampleto the left atrial appendage or the base thereof. In some instance, thecinchable loop 950 is constructed of a plastic or similar flexiblematerial. As shown here, a rotary drive may include one or more splineswhich engage one or more grooves of a gear. For example, rotary drive920 may include one or more splines 926 which engage one or more grooves946 of a gear 942. Relatedly, rotary drive 930 and gear 944 may includesimilar corresponding features.

In use, a physician or operator can actuate a knob or other aspect ofthe system so as to rotate the first rotary drive 920 in a firstdirection (e.g. as indicated by the counter-clockwise arrow A), which inturn rotates the second rotary drive 930 in a second direction (e.g. asindicated by the clockwise arrow B). In this way, the groove or slotportions 956 a, 956 b (and corresponding ligature thread portions 960 a,960 b) can turn toward one another, as indicated by arrows C. Similarturning motions are illustrated by the system configuration transitionfrom FIG. 8A to FIG. 8B, and by the system configuration transition fromFIG. 8C to 8D. In this way, a delivery control mechanism that includes afirst rotary drive coupled with a first section 810 a of a cinchableloop 810 and a second rotary drive coupled with a second section 810 bof the cinchable loop, can be actuated such that rotation of the firstrotary drive drives counter-rotation of the second rotary drive and therotating drives coordinate to switch the cinchable loop from a firstconfiguration (e.g. FIGS. 8A, 8C) to a second configuration (e.g. FIGS.8B, 8D). When in the second configuration, tension in the suture mayfacilitate unloading of the suture loop 820 from the carrier groove 830.When the thread loop has been delivered to the anatomical site, theoperator may then remove the proximal tail thread from the translatingknob, or clip the proximal tail portion at location X as indicated inFIG. 9A, so that the ligature delivery system, optionally along with thesuture carrier tube, may be withdrawn or removed from the patient.

Accordingly, a delivery control mechanism 150 such as that depicted inFIG. 1 can effect coordinated axial rotation between a first end portion113 of the delivery mechanism 110 and a second end portion 114 of thedelivery mechanism 110, where the first and second end portions 113, 114bound a central or distal portion 115 of the cinchable loop 112. Hence,with returning reference to FIGS. 9A and 9B, in some embodiments adelivery control mechanism may include a gearbox assembly 940 inoperative association with the first end portion 952 and the second endportion 954, such that the gearbox assembly effects coordinated axialrotation of the first end portion 952 and the second end portion 954.Further, as depicted here, the first rotary drive 920 can be coupledwith the first section 952 of the cinchable loop and the second rotarydrive 930 can be coupled with the second section 954 of the cinchableloop, such that applied torque is transmitted between the first andsecond rotary drives to rotate the torqueable cinchable loop 950. Inthis way, a torque or twisting or rotating force applied to one rotarydrive is transmitted to the other rotary drive, and the combinedrotating action of the rotary drives operates to rotate the cinchableloop, or that portion of the thread delivery mechanism bounded by thefirst and second rotary drives. In some cases, the support mechanism 980has an engagement assembly 981, such as a slot, a recess, a groove, or aclamp, that receives or engages the carrier 967 of the ligatureassembly. In some cases, the support mechanism 980 has an engagementassembly 983 that includes a first aperture or guide 982 and a secondaperture or guide 984. For example, the engagement assembly 983 mayinclude a first lumen or channel 982 and a second lumen or channel 984,such that a first rotary drive 920 can be disposed within the firstchannel 982 and coupled with the first section 952 of the cinchableloop, and the second rotary drive 930 can be disposed within the secondchannel 984 and coupled with the second section 954 of the cinchableloop, where the first rotary drive 920 is rotatable and translatablewithin the first channel or guide 982 and the second rotary drive 930 isrotatable within the second channel or guide 984.

With regard to the process of sizing the ligature loop to the anatomicalfeature, it can be seen that the first portion 952 of the cinchable loopis slidably received within or along a first aperture or guide 972 ofthe deflector mechanism 970, and the first portion 952 is also slidablyreceived (together with the first rotary drive 920) within or along afirst aperture or guide 982 of the support mechanism 980. Hence, whenfirst rotary drive 920 is retracted proximally as indicated by arrow P1,the first portion 952 of the cinchable loop is similarly retractedproximally through or along aperture or guide 972 as indicated by arrowP2, and also proximally through or along the first aperture or guide 982(together with the first rotary drive 920) as indicated by arrow P3.Second rotary drive 930 may rotate within or relative to a secondaperture or guide 984 of the support mechanism. According to someembodiments, however, the second rotary drive 930 may not translatelongitudinally, or otherwise remain translationally fixed, relative tothe support mechanism. Correspondingly, the second portion 954 of thecinchable loop 960 may remain fixed translationally relative to a secondaperture or guide 974 of the deflector mechanism 970, yet may be able torotate within or relative to the aperture or guide 974. When the firstrotary drive 920 is retracted proximally, the first ligature threadportion 960 a also can be drawn proximally through or along thedeflector mechanism 970, through the ligature knot 965, and through theligature thread carrier tube 967. A conical pocket or tab assembly 987of the support mechanism 980 can hold or receive a distal section of theligature assembly carrier tube 967. The pocket can be shaped or sized soas to accommodate any of a variety of shapes and sizes of carrier tubes.In some instances, the pocket 987 can be used to locate the carrier tubewhen the ligature assembly is loaded into the ligature delivery system.The pocket 987 can also be used to temporarily attach the carrier tube967 to the ligature delivery system. The pocket 987 can also include aslot or aperture through which the ligature thread can be passed whenloading the ligature assembly onto the ligature delivery system.

Although the rotary drives are generally shown as linear in shape, it isunderstood that embodiments of the present invention encompass curved orflexible rotary drives as well. For example, first and second rotarydrives 920, 930 may be constructed of a braided tube that can flex orbend about its central longitudinal axis. Relatedly, a support mechanismmay be curved or have curved lumens or channels 982, 984 in which suchflexible rotary drives may rotate. Although the default orientation ofthe cinchable loop and deflector mechanism is often shown to have a zerodegree yaw deflection with regard to the support mechanism, it is alsounderstood that the deflector mechanism may be constructed to provide anoffset relative to the support mechanism (e.g. 45 to 90 degrees yaw)when in a default or unactivated configuration.

Use with Alternative Ligature Assemblies

In the embodiments depicted in FIGS. 9A and 9B, the ligature assemblyincludes a carrier tube 967, and a ligature thread having a proximaltail 964, a knot 965, and a distal loop portion 960 a, 960 b. As shownin FIG. 9B, a distal section 968 of the carrier tube 967 can be used toproviding an opposing force against the knot 965 when a translatingportion 960 a of the thread is pulled proximally through the knot 965.In some instances, however, a ligature assembly may not include acarrier tube or knot pusher. For example, with reference to FIGS. 2A and2B, a ligature assembly may include a knotted ligature thread having aproximal tail and a distal loop, and no carrier tube or pusher. In somecases, with reference to FIG. 2C, a ligature assembly may include aproximal tail portion, and a distal portion which can be formed into aloop by passing the proximal portion through a ratchet mechanism. Hence,embodiments of the present invention encompass systems that provide ameans for providing an opposing force against a knot or ratchetmechanism, for example in cases where a ligature assembly does notinclude a carrier tube or knot or ratchet pusher. As depicted in FIG.9B, the deflector mechanism 970 may include a pocket or stop 971 thatreceives a ligature assembly knot or ratchet, and the pocket or stop 971can be used to provide an opposing force when drawing the translatingportion 960 a of the ligature thread or device through the knot orratchet mechanism, so as to cinch or reduce the diameter of the ligatureloop. It is understood that such a pocket or stop can also be placed atany suitable location on the support mechanism 980, for example at ornear the location where tabs or conical pocket 987 are used to hold adistal portion of the carrier tube 967.

Additional Features of System Operation

FIGS. 10A and 10B illustrate aspects of a ligature delivery system 1000for use with a ligature assembly 1010 according to embodiments of thepresent invention. As shown here, the ligature assembly 1010 includes acarrier tube 1012 having a main body 1014, and a frangible portion 1016which has been detached from the main body 1014. The frangible portion1016 is fixed with a proximal tail portion 1018 of the ligature thread.In addition to, or as an alternative to, the pin and groove featuresdepicted in FIG. 3B for example, a rotatable and translatable knob 1022of a delivery control mechanism 1020 may include a channel or pocket1024 that releasably coupled with the frangible portion 1016. Hence,when the knob is retracted proximally, or translated axially, relativeto the support mechanism or handle 1030 as indicated by arrow A, thefrangible portion 1016 is also drawn proximally in the directionindicated by arrow A. Accordingly, cinching of the thread deliverymechanism loop is coincident with cinching of the ligature thread loop.In some instances, the frangible portion or break-off pull handle 1016attached with the proximal tail end of the suture can be wedged into thegroove 1024 of the rotary knob 1022, so as to keep axial movement of thesuture carrier loop the same as that of the suture thread itself.

The ligature delivery system 1000 may also include a spring loaded orbiased catch mechanism 1040, which can be used to hold or secure aproximal portion of the carrier tube main body 1014. For example, thecatch 1040 can be biased to press against the main body 1014 in thedirection indicated by arrow B. As seen in the cross-section view ofFIG. 10B, the ligature delivery system may include a spring or otherbiasing element 1041 that operates to press or bias the catch 1040toward a distal direction as indicated by arrow B. In this way, thecatch mechanism 1040, in combination with the recess 981 and pocket 987shown in FIG. 9B, can releasably secure or engage the carrier tube ofthe ligature assembly with the support mechanism. The catch mechanism1040 can include an aperture or lengthwise slot through which theligature thread can be passed when loading the ligature assembly ontothe ligature delivery system. In some instances, the catch mechanism1040 may include a lip or edge 1040 a that helps secure a proximalsection 1014 a of the carrier tube in place, relative to the supportmechanism. Similarly, as shown here, the handle or support mechanism1050 may include a lengthwise slot through which the ligature thread canbe passed when loading the ligature assembly onto the ligature deliverysystem. FIGS. 10A and 10B also illustrate that a ligature deliverysystem can include a deflection control mechanism 1070 having anactuation assembly 1072 and a linkage assembly 1074 coupled with adeflector mechanism (not shown). The actuation assembly 1072 shown hereincludes a sliding or thumb-actuated button or lever 1073 that can betranslated relative to the support mechanism distally or proximally asindicated by arrow C. As seen in the embodiment depicted by FIG. 10C,the catch 1040 c may include tabs, prongs, or guides 1042 c for engagingthe support mechanism or handle 1050 c, so as to facilitate relativetransitional movement (as indicated by arrow A) between the catch 1040 cand the support mechanism 1050 c, when loading or discharging a mainbody 1014 c of a ligature assembly. For example, the catch 1040 c can bedrawn proximally when unloading a used carrier tube and re-loading a newligature assembly, and moved distally once the new ligature assembly isin place, thus securing the main body 1014 c relative to the supportmechanism.

FIG. 11 shows an end distal view of an exemplary ligature deliverysystem 1100. As depicted here, each of the support mechanism 1110 andthe deflector mechanism 1120 may include one or more apertures,channels, or guides for receiving fiber optic light sources ortransmission means, imaging or visualization devices or means,irrigation fluid or means, suction devices, grasping devices such asforceps, and the like. For example, support mechanism 1110 may include alongitudinally extending passage or lumen 1112 that houses or receives afiber optic light transmission assembly. Similarly, deflector mechanism1120 may include an aperture or passage 1122 that also receives thefiber optic light transmission assembly. In this way, the operator oruser can visualize the anatomical environment in which the cinching loopis placed, and the anatomical feature to which the ligature thread isapplied. Hence the ligature delivery system may also include or beconfigured for use with a light source. In some cases, operation of adelivery or applicator system can include the use of an endoscope, withor without protective sheath, or a light wand or LED to enhancevisualization. In some cases, a light wand or LED may be integral with ashaft of the delivery or treatment device.

Optionally, the lumens or apertures 1112, 1122 may house or receive anirrigation tube or provide a passage for delivering an irrigation fluidto the surgical area or a desired anatomical structure. Hence theligature delivery system may also include or be configured for use withan irrigation fluid source.

In some instances, the lumens or apertures 1112, 1122 may house orreceive a suction tube or provide a passage for delivering suction or avacuum to the surgical area or a desired anatomical structure. Forexample, suction or negative pressure provided via such a feature canoperate to secure or grasp an anatomical feature within the patient, soas to grasp a particular anatomical structure or positionally stabilizethe ligature delivery system relative to the surgical area. Hence theligature delivery system may also include or be configured for use witha suction or vacuum source. A suction member can seal or interface withan anatomical feature such as the left atrial appendage, so as to adhereto or grasp the tissue, so that the anatomical feature can be extendedor maneuvered as desired, and an occlusive device or ligature thread canbe delivered to the anatomical feature. In some instances, the lumens orapertures 1112, 1122 may house or receive a grasping mechanism such as aforceps, which can be used to manipulate various anatomical structuresof the patient. For example, a forceps device delivered through thelumens or apertures 1112, 1122, may be used to secure or grasp ananatomical feature within the patient, or to grasp a particularanatomical structure or positionally stabilize the ligature deliverysystem relative to the surgical area. Hence the ligature delivery systemmay also include or be configured for use with a grasping mechanism orforceps device. A grasping mechanism or forceps can releasably attachwith an anatomical feature such as the left atrial appendage, so as toadhere to or grasp the tissue, so that the anatomical feature can beextended or maneuvered as desired, and an occlusive device or ligaturethread can be delivered to the anatomical feature.

In some instances, a suction cone or cup can be extended distally beyondthe distal end of the closure delivery means. In this way, the suctionmeans can attach to or engage the LAA. By operating handle mechanisms ofthe treatment system, the closure delivery means can be advanced distalto the suction means, and can be used to deliver the closure means orligature to the base of the LAA. The snare or ligature can be tightenedabout the LAA, and activation of a system trigger can release the suturein place about the LAA.

With returning reference to FIGS. 4A and 4B, a ligature delivery system400 may include a ligature assembly discharge mechanism 490 operable bya system user to discharge the ligature assembly carrier tube 412 a fromthe support mechanism 430. For example, the discharge mechanism 490 mayinclude an ejector 492 coupled with a catch 494 via a linkage 496. Inuse, the operator may retract the catch 494 proximally, which draws thelinkage proximally, which in turn draws the ejector proximally 492, thusforcing the carrier tube 412 a away from the support mechanism 430.Optionally, the operator may advance the catch 494 distally, thusforcing the distal portion of the carrier tube 412 a against the wedgeshaped ejector 492, such that the distal carrier tube portion slidesalong the ejector in a ramping fashion, thus expelling the carrier tube.In some instances, the discharge mechanism can be actuated once thedelivery system and carrier tube have been withdrawn from the patient,following application of a cinched ligature loop. In some instances, aligature delivery system may not include such a discharge mechanism, anda surgeon or operator may simply remove the carrier tube from thesupport mechanism by grasping the carrier tube and retracting thecarrier tube from the engagement mechanism or channel in which thecarrier tube was loaded.

As depicted in FIG. 12, a ligature delivery system 1200 can be used inconjunction with a tissue grasping or engagement mechanism 1250. Hence,a surgeon or operator can perform discrete operations with two differentdevices. That is, the tissue engagement mechanism 1250 can be used tograsp, maneuver, hold, or position the patient anatomy (e.g. left atrialappendage) as desired, and the ligature delivery system 1200 can be usedto deliver a ligature loop or closure means to the patient anatomy.Hence, according to one embodiment, a surgical procedure may includeapproaching the patient anatomy or left atrial appendage with theengagement mechanism 1250, and fixing the engagement mechanism to thepatient tissue. For example, the procedure may include applying asuction or vacuum through an elongate tubular member 1252 and thesuction cup or cone 1254, so that the suction cup 1254 securely sealswith the patient anatomy. The elongate tubular member and/or suction cupmay be bendable, rotatable, and flexible as needed for any particularapplication. In a left atrial appendage procedure, the surgeon oroperator can draw a portion of the LAA into the suction cup 1254 andmaneuver the engagement mechanism 1250 so as to expose the base of theLAA. While holding the LAA in place with the engagement mechanism 1250,the surgeon can then advance the cinchable loop 1210 of the ligaturedelivery system distally along the elongate tubular member 1252 asindicated by arrow A, and over the suction cup 1254. Hence, instead ofmaneuvering the cinchable loop directly over the patient anatomicalstructure as described elsewhere herein the surgeon or operator canmaneuver the cinchable loop over the engagement mechanism (which isalready in contact with the patient structure). In some instances, theengagement mechanism 1250 and the ligature delivery assembly 1200 may beinserted into the patient via different or separate access locations orports (e.g. engagement mechanism via a sternotomy, and ligature deliveryassembly via a thoracotomy). In some instances, the engagement mechanism1250 and the ligature delivery assembly 1200 may be inserted into thepatient via a common access location or port. In some cases, theengagement mechanism and delivery assembly may be used during anopen-heart procedure.

As shown here, the suction cup 1254 may include a rim or circumferentialsealing portion 1255 that can be used to engage the base or the leftatrial appendage. With the suction cup 1254 engaged with the left atrialappendage, and the cinchable loop 1210 disposed about the suction cup1254, the surgeon or operator can cinch the loop 1210, optionally whilesliding the loop further distally along the cup, or rolling the loopdistally over the surface of the cup. In some instances, the shape ofthe suction cup can help to deliver the cinchable loop 1210 to the baseof the left atrial appendage. For example, the suction cup may have adistally tapering portion 1256, such that when the cinchable loop istightened against or rolled along the suction cup, and advanced distalto the equator of the cup, the cinchable loop is guided toward thedesired anatomical target (e.g. base of the left atrial appendage). Insome instances, the materials of the cinchable loop and suction cup maybe configured to provide traction therebetween, which can facilitaterolling of the cinchable loop against the outer surface of the suctioncup. For example, either or both of the cinchable loop and suction cupmay include a rubbery outer material or textured surface. Once thecinchable loop has been placed about the left atrial appendage, cinchedas desired, and rotated so as to orient the suture thread loop to thedelivery position, the suture thread loop can be unloaded from thecinchable loop and delivered to the patient tissue. For example, thesuture loop can be applied to the patient tissue at or near where therim or circumferential sealing portion 1255 engages the patient tissue.

In some instances, the shape and size of the suction cup 1254 may beconfigured specifically for use with a particular anatomical structureof the patient. For example, the shape and size of the suction cup maybe configured for engagement with the left atrial appendage of apatient. In some instances, the rim 1255 is curved, and presents alaterally compressed, truncated cone shape. The rim 1255 can be shapedand sized to match the surface of the heart or the base of the leftatrial appendage. In some instances, a suction cup 1254 may present anelongate trumpet shape, that can be easily collapsible, compressed intoa small shape, and delivered through an access port (e.g. 12 mm port),and then opened into the trumpet shape after insertion into the patient.When drawing the left atrial appendage into an elongate trumpet-shapedsuction device, the trumpet-shaped device can operate to squeeze bloodout of the left atrial appendage as the left atrial appendage iscompressed by the trumpet-shaped suction cone. As depicted in the widerconfiguration of FIG. 12, when drawing the left atrial appendage intothe suction cup 1254, the bulb-shaped or prolate suction device drawsthe left atrial appendage in, and operates to expand the left atrialappendage. In this way, blood is not forced out of the left atrialappendage, but rather remains in the left atrial appendage. Once theleft atrial appendage is cinched, the trapped blood therein mayeventually form a clot and be absorbed within the body with no adverseeffect. Accordingly, the suction cup 1254 is sufficiently strong orrigid to maintain its shape upon application of the suction, and is alsosufficiently flexible to be folded or compressed and inserted into apatient via a port or access site (e.g. between the ribs, in athoracotomy).

In some instances, the engagement mechanism 1250 may include a flexibleor rotatable joint or connection 1258 between the elongate tube 1252 andthe suction cup 1254. For example, the engagement mechanism 1250 mayinclude a joint or connection similar to that described elsewhere hereinwith regard to the joint or connection between the support mechanism andthe deflector mechanism of the ligature delivery assembly. In somecases, the joint or connection may include a ball joint or a hingejoint. The engagement mechanism may also include a deflection controlmechanism, which operates to actuate the suction cup in pitch and yaworientations, similar to that described elsewhere herein with regard tothe deflection control mechanism of the ligature delivery assembly. Insome cases, the deflection control mechanism of the engagement mechanismmay include linkages, push-pull rods, and the like, which can rotate ordeflect the suction cup as desired, for example so as to angle thesuction cup for facile engagement with the left atrial appendage of apatient. Relatedly, such deflection control mechanisms can be used toactuate the joint or connection 1258, or otherwise maneuver suction cup1254 relative to the elongate tube or handle 1252. In some cases, anengagement mechanism 1250 may be manufactured so as to provide a fixedangle or relative positional relationship between the suction cup 1254and the elongate tube 1252. In some cases, an engagement mechanism 1250may be manufactured so as to provide an adjustable angle or relativepositional relationship between the suction cup 1254 and the elongatetube 1252. In some cases, an engagement mechanism 1250 may include anelongate tube 1252 having an adjustable length. In some cases, theengagement mechanism 1250 may provide for adjustable pitch of thesuction cup 1254 relative to the elongate tube 1252. In some cases, theengagement mechanism 1250 may provide for adjustable yaw of the suctioncup 1254 relative to the elongate tube 1252. In some cases, theengagement mechanism 1250 may provide for both adjustable pitch andadjustable yaw of the suction cup 1254 relative to the elongate tube1252. In some cases, the engagement mechanism 1250 may provide foradjustable pitch, adjustable yaw, adjustable roll, or any combinationthereof, of the suction cup 1254 relative to the elongate tube 1252.

In some instances, the engagement mechanism 1250 may be used, withoutassistance from the ligature delivery assembly 1200, to deliver aligature loop or closure means to a patient tissue. For example, asurgeon or operator can place a distal portion of a ligature assemblycarrier tube at a stop or tab 1262 of the suction cup 1254. The stop ortab 1262 may include a slot 1264 and an aperture or conical pocket 1266which receive the ligature thread, and the ligature loop can be wrappedabout a groove, recess, or other thread engagement feature 1268 that isdisposed about the cup rim or margin 1255. Hence, the distal tip of thecarrier tube can be inserted into or engaged with the conical pocket1266. With the distal tip of the snare or carrier tube (not shown)engaged with the stop or tab 1262, and the suture thread loop (notshown) wrapped about the suction cup so as to engage the groove 1268,the suction cup 1254 can be placed into position relative to the patientanatomical feature (e.g. about the base of the left atrial appendage),optionally with applied suction to secure the anatomical feature to thesuction cup, and the suture can be tightened so as to more closelyapproximate the anatomical feature. In this way, the presence of thesuction cup can help to shield or protect the patient tissue from thesuture thread as the thread is cinched about the patient tissue. Forexample, any slicing or cutting effect the cinching suture may otherwisehave on the patient tissue is avoid, due to the presence of the suctioncup which is disposed between the thread and the tissue. When the sutureis placed and tightened as desired, the surgeon or operator can roll orunload the suture loop from the groove 1268, over the cup rim 1255, andonto the patient tissue. Optionally, the surgeon or operator maythereafter further cinch the suture, remove the distal carrier tubeportion from the stop or tab 1262, withdraw the engagement mechanism,withdraw the carrier tube, and/or sever the suture thread, for exampleas describe elsewhere herein. In some instances, the engagementmechanism 1250 and the ligature assembly may be inserted into thepatient via different or separate access locations or ports (e.g.engagement mechanism via a sternotomy, and ligature assembly via athoracotomy). In some instances, the engagement mechanism 1250 and theligature assembly may be inserted into the patient via a common accesslocation or port. In some cases, the engagement mechanism and ligatureassembly may be used during an open-heart procedure. In some instances,cinching of the ligature thread loop and contraction of the suction cup,optionally due at least in part to suction applied through the elongatetube, can be performed in a coordinated fashion.

In use, the shaft 1252 can be approximated to the LAA, and the suctionmeans 1254 is used to grasp the LAA. The closure delivery means 1200 canbe used to slide or advance a looped ligature over or along the suctionmeans 1254 in a proximal direction, and to further slide or advance thelooped ligature over the LAA. In this way, the shaft 1252 and suctionmeans 1254 can be used as a guide for approximating the closure deliverymeans 1200 toward the LAA, for example to deliver an epicardialocclusion device or closure means. The shaft 1252 and suction means 1254allows the operator to gain traction relative to LAA, in order to placethe closure means on the LAA. When the ligature or closure means issituated as desired, for example about the base of the LAA, the closuremeans can be actuated or cinched, thereby applying a squeezing orcircumferential compression force to the LAA, and optionally tied inplace so that it remains about the LAA. Any of a variety of closuremeans may be used, including cinching ligatures, clips, clamps, sutures,or combinations thereof. The treatment systems disclosed herein are wellsuited for safely, effectively, and efficiently delivering closure meansto the LAA, while minimizing the risk of tearing the LAA or forming onlya partial or incomplete closure of the LAA which may lead to undesirableblood clot formation within and release from the LAA.

According to some embodiments, the leading edge or portion of thesuction member or suction cup 1254 may house or attach with portions ofa ligature or closure means. For example, a ligature loop may becircumferentially associated with a distal portion of the suction means.Optionally, a distal portion of the suction means may include a tube orchanneled portions which hold the looped closure means. The tube mayinclude an annular tube ring, for example, having an inner channel whichreceives the suture. Such tubing or distal portion can be used todeliver the suture as desired.

In some cases, treatment systems can be used to deliver a closure meansduring an open surgical procedure. In some cases, treatment systems canbe used in conjunction with ports to deliver a closure means during aminimally invasive surgical procedure.

In some cases, a suction member may be configured with a rigid tubewhich acts as a guiding rail to pass the occlusive member over, forexample in the case of a lasso or band type device. Relatedly, the rigidtube can acts as a guiding rail to pass the occlusive member along, forexample in the case of a clip type device.

According to some embodiments, a suction member or grasping device andan applicator mechanism or suture carrier can provide opposing forces toallow delivery of the occlusive device at the base of the appendageorifice. An applicator system can be guided along the suction memberrail and can be activated by an activation mechanism to deliver theocclusive device.

In some instances, an exemplary treatment system can include a shaftwith a distal portion and proximal portion. The system can include asuction means, such as a suction cup, for attaching with or grasping theleft atrial appendage. The system can also include a closure deliverymeans which can be used to deliver or apply a closure means, such as aligature, ratchet lock, crimp, or slip knot, to the base of the LAAthereby occluding or closing the LAA, or segregating the LAA from theleft atrium. In some instances, an exemplary treatment system may alsoinclude a scope accessory or other visualization mechanism. In somecase, the visualization mechanism is separate from the closure deliverymeans or shaft. In some cases, the visualization mechanism is integralwith the closure delivery means or shaft. In some cases, the shaft,suction means, and closure delivery means may be integrated in a singleapparatus, which optionally may also incorporate a visualization means.In some instances, the suction means can present a flared orfunnel-shaped distal portion, such as a suction cup or element, thatinterfaces and receives or adheres to a portion of the LAA.

In some cases, the deflection control mechanism, support mechanism,shaft, or other element of the system may include a linkage system thatcauses the rotation of the suction cup to be about a virtual pivot point(VPP) that may be on or close to the plane of the left atrial base, orany other point away from actual mechanism in order to optimize themovement of the engagement system in the tight confines of surgery. Forexample, as depicted in FIGS. 12A-1, 12A-2, and 12A-3, a ligaturedelivery system or tissue engagement mechanism 1250 a can be used tograsp, maneuver, hold, or position the patient anatomy (e.g. left atrialappendage) as desired, and can also be used to deliver a ligature loopor closure means to the patient anatomy. Hence, according to oneembodiment, a surgical procedure may include approaching the patientanatomy or left atrial appendage with the engagement mechanism 1250 a,and fixing the engagement mechanism to the patient tissue. For example,the procedure may include applying a suction or vacuum through a tubularmember 1252 a and the suction cup or cone 1254 a, so that the suctioncup 1254 a securely seals or engages with the patient anatomy. As shownhere, the engagement mechanism 1250 a provides a virtual pivot point(VPP) that remains consistent as the engagement mechanism is movedbetween position 1 (FIG. 12A-1), position 2 (FIG. 12A-2), and position 3(FIG. 12A-3). In this embodiment, the engagement mechanism includes anon-parallel four bar linkage system 1260 a, where a handle 1270 ahaving a T-shaped distal end provides one link in the linkage system.The links can be provided in various lengths, which can move the virtualpivot point (VPP) along the dashed line or axis 1280 a to a desiredpoint.

FIGS. 13A and 13B illustrate another embodiment of an engagementmechanism 1350 for use with a ligature assembly, optionally inconjunction with a ligature delivery assembly. As shown here, theengagement mechanism includes a suction cup 1354 having a plurality offingers or elongate extensions 1370. The suction cup 1354 may alsoinclude a very thin membrane (not shown) similar in consistency to thatof a surgical glove, which covers the spacings 1380 between the fingers1370. In this way, the suction cup 1354 can provide an enhanced degreeof flexibility between the fingers, and can also provide uninterruptedsuction to an anatomical feature to which the suction cup is applied.The fingers 1370 can provide a degree of structural rigidity to thesuction cup (relative to the membrane covering the spacings 1380, so asto maintain the overall shape of the suction cup, and the fingers 1370can also fold or bend in a controlled manner upon application of suctionand/or tightening of the suture loop. In use, tightening of the sutureor ligature thread can operate to close the flexible fingers toward eachother. In some instances, the distal tips of the fingers can touchtogether, or almost touch together, when the suction cup is contractedor constricted (e.g. due to the suction applied and/or cinching of thethread). The overall shape of the suction cup 1354 can be provided as atrumpet-shape, a football or prolate-shape, or any other desired shape,including a shape that may be shorter in height than in width or lengththat is not designed to withdraw the appendage within but rather to suckonto the external surface of the appendage for manipulation. In someinstances, flexible flaps, which are coupled with the flexible fingers,hold the suture in a looped configuration. The flaps may have distalslotted tube sections which can release the ligature when the flaps aredrawn radially inward. Hence, as the suture or ligature is drawn taught,the flaps bend inward, thus allowing the ligature to release through theslots, and situate about the LAA. In operation, an ligature assembly(not shown), optionally in conjunction with a ligature delivery assembly(not shown) can be used with the engagement mechanism 1350 in any of themodalities described elsewhere herein, and in particular according tothe techniques discussed above with regard to FIG. 12.

In some instances, an engagement mechanism may include an elongate tubecoupled with a suction cup, where the suction cup has a shape configuredto interface with an anatomical feature of the patient (including ashape as noted in the preceding paragraph, or as described elsewhereherein). The suction cup may be void of tab, groove, and/or fingerfeatures those described herein with regard to FIGS. 12, 13A, and 13B.In use, the suture loop may be advanced over the suction cup anddelivered to the anatomical site (e.g. base of left atrial appendage) asdesired.

FIG. 14 illustrates aspects of an exemplary method according toembodiments of the present invention. Procedure 1400 includes obtaininga ligature assembly or suture device as indicated by step 1405, forexample by removing the ligature assembly from a sterile package. Insome instances, the ligature assembly may include a ligature suturedisposed partially within a tubular body or pusher. The procedure mayalso include preparing the suture or ligature assembly by removing afrangible portion of the carrier tube or pusher from a main body of thepusher, as indicated by step 1410. In some instances, this step mayinvolve breaking off the proximal pull tab of a carrier tube. Further,the procedure may include loading the carrier tube (e.g. main body) ontoa support mechanism of a ligature delivery system as indicated by step1415. For example, a distal section of the carrier tube main body can beengaged with a distal cone or pocket of the support mechanism, and aproximal section of the carrier tube can be engaged against a springloaded clip or catch mechanism. The operator or surgeon may alsoslightly retract a proximal tail of the ligature thread, for example bypulling the frangible portion of the dissociated carrier tube proximallya distance of about one inch, to verify which side of the ligature loopremains stationary and which side is drawn proximally through the loop,as indicated by step 1420. The stationary portion of the ligature threadloop can be inserted into the thread delivery mechanism groove at alocation near a non-translating rotary drive, as indicated by step 1425.The ligature thread loop can then be worked around the groove of thecinchable loop carrier of the thread delivery mechanism. A proximal tailof the ligature thread can be fixed relative to a first rotary drive, asindicated by step 1430. For example, the operator may pull the frangibleportion of the suture tube to take up slack in the ligature thread, andwedge the frangible portion into a rotary knob slot of a deliverycontrol mechanism. Additionally, the procedure may include inserting thedistal portion of the system into a patient's body, or advancing thedistal portion to a desired anatomical location of the patient,adjusting the pitch, yaw, or both of the cinchable loop, and positioningthe cinchable loop about an anatomical feature of the patient, such asthe left atrial appendage (LAA), as indicated by step 1435. The operatormay pull or retract the rotary knob or first rotary drive, so as totighten or cinch the cinchable loop as indicated by step 1440. Further,as indicated by step 1445, the operator can turn the rotary knob orotherwise actuate the first rotary drive, so as to deploy the suturethread to the anatomical structure, as indicated by step 1450. With theligature loop appropriately positioned about the anatomical structure,the operator can grasp or tug on the exposed proximal suture portion,and cut the suture thread, so as to decouple the cinched suture loopthat is engaged with the anatomy from the system that has performed thesuture delivery and cinching, as indicated by step 1450. Often, prior tothis decoupling, the ligature snare and the delivery system are presenttogether or otherwise engaged as a single unit. The operator may alsopush in or distally advance the rotary knob so as to loosen thecinchable loop from its grip on the anatomical feature, and remove orwithdraw the device from the applied suture strand and anatomicalstructure as indicated by step 1455. At this point, the ligaturedelivery system along with the carrier tube can be withdrawn from thepatient, leaving the suture in place (for example with the ligature loopdisposed about the patient's LAA, and the proximal tail of the ligaturethread extending out of the patient's body through an access port orother opening). The surgeon or operator can then slide a pair ofscissors or other cutting device along the proximal tail thread, in adistal direction toward the cinched loop. When the scissors are near theknot, the surgeon can then clip the thread at a location proximal to theknot, and remove the severed proximal tail and scissors from thepatient, thus leaving the cinched and knotted suture loop disposed aboutthe patient anatomical feature as an implanted medical device. Asdepicted by step 1460, the operator may also remove the suture tube fromthe support mechanism by sliding a clip or catch proximally relative tothe support mechanism, thus discharging the suture carrier tube from thesupport mechanism. The wedged pull tab or frangible portion may also beremoved from the rotary knob. As desired, this procedure can be repeatedso as to apply multiple ligature threads to one or more anatomicalstructures of the patient's body. Hence, the ligature delivery systemcan be repeatedly reloaded with any desired number of ligatureassemblies to deliver any number of cinched loop implants.

As discussed elsewhere herein, in some instances a ligature assembly mayinclude a knotted thread or suture having a distal loop portion and aproximal tail portion, without a carrier or push tube. FIG. 15illustrates such a ligature assembly 1500 having a proximal tail portion1510, a one-way knot 1520, and a distal loop 1530. In this brokenperspective view of the ligature delivery system 1540, which shows a topview of a proximal portion 1542 of the system and a bottom view of adistal portion 1544 of the system, it can be seen that a supportmechanism or deflector mechanism 1550 may include a pocket or stop 1551that receives the ligature assembly knot 1520. In some instances, thepocket or stop may include a slotted shelf or two protrusions whichoperate to prevent proximal translation of the knot relative to thesupport mechanism or deflector mechanism when the tail portion 1510 ofthe ligature assembly is drawn proximally. Hence, for example, a portionof the thread disposed proximal to the knot, as indicated by location A,can be threaded in the slot 1552 of the pocket. It is understood thatsuch a pocket or stop can also be placed at any suitable location on thesupport mechanism or on the deflector mechanism. It can also be seenhere that the proximal tail portion 1510 of the ligature assembly can beengaged with the ligature delivery assembly, for example by winding theproximal tail portion about a proximal knob 1560, or by fixing theproximal tail portion 1510 relative to a first rotary drive as discussedelsewhere herein. In use, the surgeon or operator can use the cinchableloop of the ligature delivery assembly to place the ligature thread loop1530 about the anatomical structure, and can use the knob 1560 to drawthe thread tail 1510 proximally, so as to cinch the thread loop relativeto the patient anatomical structure. Accordingly, the yoke or stop 1551can be used to provide an opposing force when drawing a translatingportion 1532 of the ligature thread proximally through the knot 1520, soas to cinch or reduce the diameter of the ligature loop. In this way,the knot is restrained by the pocket. The translating portion 1532 ofthe thread passes through the one-way knot 1520 and toward the proximalportion 1542 of the delivery system. In this way, the loop thread can becinched by applying counter traction via the knob and pocket. Thesliding knot operates to secure itself when tightened. Once tightened inplace relative to the anatomical structure, the suture thread loop orclosure means can be unloaded from the cinchable loop of the ligaturedelivery device, thus also releasing the knot from the pocket.Thereafter, the suture loop or closure means remains in place about theanatomical structure (e.g. by virtue of the one-way knotted loop). Theproximal tail portion 1510 can be released from the knob, and theligature delivery device can be removed or retracted away from thepatient, leaving the suture thread fixed to the patient anatomy. Thesurgeon or operator can then clip the excess proximal tail portion ofthe suture thread. In this way, the closure means or ligature loop canbe used to tie off the left atrial appendage of a patient, the cecalappendix, or any other desired structure within a patient.

Different arrangements of the components depicted in the drawings ordescribed above, as well as components and steps not shown or describedare possible. Similarly, some features and subcombinations are usefuland may be employed without reference to other features andsubcombinations. Embodiments of the invention have been described forillustrative and not restrictive purposes, and alternative embodimentswill become apparent to readers of this patent. Accordingly, the presentinvention is not limited to the embodiments described above or depictedin the drawings, and various embodiments and modifications can be madewithout departing from the scope of the claims below.

While exemplary embodiments have been described in some detail, by wayof example and for clarity of understanding, those of skill in the artwill recognize that a variety of modification, adaptations, and changesmay be employed. Hence, the scope of the present invention should belimited solely by the claims.

We claim:
 1. A ligature delivery system for use with an anatomicalstructure closure mechanism, the ligature delivery system comprising: adelivery mechanism comprising a cinchable loop that engages the closuremechanism and that rotates axially about a central longitudinal axisbetween a first configuration whereby the closure mechanism is shieldedfrom the anatomical structure of a patient and a second configurationwhereby the closure mechanism can be released onto the anatomicalstructure; and a delivery control mechanism that cinches the cinchableloop about the anatomical structure and that switches the cinchable loopbetween the first and second configurations.